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Senior Product Manager Mike Gough explores Sir Kenneth’s pioneering designs and discusses the rarity of using an industrial designer in the early 1970s for loudspeaker design.

I joined Bowers & Wilkins in late 1987 as a speaker engineer, by which time Kenneth Grange was firmly established as the industrial designer for the company and held in some awe by those who worked with him.

Kenneth was introduced to John Bowers in the early 1970s by their mutual friend Lord Snowdon, photography being a common interest. In those days, speaker design was almost totally in the hands of acoustic engineers and the concept of using an industrial designer, who could add flair to the looks of a product, was rare.

Redefining loudspeaker design

This state of affairs was undoubtedly a key reason why speakers were seldom accepted as a legitimate object in the living space. They were traditionally large – at best functional; at worst downright ugly.

Kenneth was by that time one of the foremost industrial designers in the country, having cut his teeth with the Instamatic camera for Kodak and going on to work with many major manufacturers of the day. The challenge of integrating the loudspeaker into what he has always described as the complex environment of the home interested Kenneth and he began his first project for B&W Loudspeakers, as the company was then known, in 1974.

Speakers are a difficult subject for the industrial designer. Their performance is directly affected by the geometry of the product and the materials from which it is constructed and so the designer does not have as free a hand as he might when working in other areas of manufacture. At that time, B&W engineers were developing Kevlar as a driver cone material and investigating the merits of time alignment between the various drivers. Kevlar imbued the cone with its now-familiar yellow colour and time aligning the drivers led to a stepped front baffle.

DM6 – The pregnant penguin

Kenneth’s original sketch (Figure 1) celebrates the technical aspect of the drivers each being mounted in a different plane by the visible slope of the veneered cabinet proper. But there is an attempt to disguise this and get closer to a more traditional rectangular shape by the use of a deep frame supporting the acoustically transparent grille fabric. This rather top-heavy result was discarded and Kenneth decided to come clean with the baffle profile and the result was the stepped design of Figure 2. In Figure 3, we see the addition of the prominent chamfer across the top edge and finally, in Figure 4, the final product as introduced in 1975.

With its distinctive shape and cantilevered support, the DM6 was soon dubbed “the pregnant penguin” and so began a new era for the company. No speaker from then on was to be left solely to the engineers. A partnership between them and Kenneth was established that brought an iterative way of working. Each party challenged the other with their desires to perfect the performance of the product and make it look more distinctive, more acceptable in the home and, simply, better.

As was the naming practice in those relatively early days, the next product was called DM7, introduced two years later in 1977.

By this time, the engineers had discovered that the dispersion of sound around the speaker – so important in creating a believable sound image – benefitted by reducing baffle size as well as driver size as frequencies went higher. So was born the tweeter-on-top concept that incorporates this reduction of baffle size and time alignmrent in one go. (Figure 5)

Unlike the 3-way DM6, the DM7 was a 2-way design, so there was no requirement to step the main baffle and a more traditional form was adopted, albeit with detail sculpting of the grille to take the edge off the basic rectangular design.

Development of the legendary 801 speaker

In the late 1970s, small speakers – so-called mini monitors – had gained popularity in Europe for their ability to present a superb stereo image. This genre was probably best epitomised by the LS3/5 speaker, designed at the BBC research facility at Kingswood Warren near London, originally for acoustic modelling and later for monitoring in the confined spaces of outside broadcast vans. What such speakers lacked was an ability to reach the lowest frequencies and to play loud.

It did not take much ingenuity to come up with the idea of sticking a mini monitor on top of a larger bass bin. Diverting the bass to a larger driver gave greater output level and bass extension, whilst retaining the smaller speaker’s imaging. So obvious was this idea that several companies produced models on this principle, but none came even close to the success of the B&W Model 801.

This speaker, first introduced in 1979, took the concept of the DM7’s separate tweeter housing one stage further with a third housing for a dedicated midrange driver. What set it apart from the competition was a combination of Grange’s classic design and the engineers’ embryonic association with EMI’s Abbey Road Studio. The 801 rapidly became that and other studios’ default choice of monitor speaker for classical music recording.

So successful was this design that it remained little altered through several technical upgrades – Series 3 eventually ceasing production in 1998. Figure 6 shows the Series 2 version, which added a port and Matrix™ cabinet bracing to the original.

CM1 and CM2 speaker

The double product design of CM1/CM2 has always been one of Kenneth’s favourites; one that he kept on display in his office for many years. This duo formed part of Concept 90, an early anticipation of the 1990s, but actually introduced in 1987.

Small speakers have always been desirable to the consumer. They are unobtrusive and image extremely well, but, as mentioned before, their inherrent inefficiency means that they don’t reach far into the bass frequencies.

CM1 was a small 2-way bookshelf speaker with a diminutive 5-inch bass/midrange driver. For the benefit of the camera, it is seen in Figure 7 on the floor, where it should never be placed in practice. The clever twist that Kenneth introduced was to angle the back section of the base of the cabinet, thus allowing the speaker to point horizontally or to tilt back as seen here. This expanded the mounting possibilities, making the product more flexible to the user.

Those desirous of a more profound bass response could either buy the floor-standing CM2 or upgrade the CM1 to the larger model at a later date by buying the supporting pillar, which houses a pair of rear-facing drivers to cover the lowest frequencies. The fact that very low frequencies wrap round objects enabled Kenneth to disguise the presence of the bass drivers and give a much cleaner look at the front.

Introduction of the Matrix 800

Hot on the heels of the 801 came the 802, essentually the same design but using smaller bass drivers for a smaller footprint. Then 1990 saw the introduction of the Matrix 800.

B&W’s engineers had always been aware of the difficulty making speakers sound as good in the often less than ideal environment of the typical domestic listening room as they did in the carefully designed auditioning room at Steyning. Room resonances were usually the culprit and one simply has to accept that consumers are not always willing to spend as much on acoustic treatment of the room as they are on the hi-fi equipment itself.

Several technical papers had suggested that multiple spaced bass drivers tended to even out these intrusive resonances and the tall Matrix 800 used two 12-inch drivers, one in the usual position near the floor and the other almost at standing head height. The midrange and tweeter were to be placed between the two at the optimum height for the seated listener and with the narrower dimensions shown to produce better dispersion of sound at higher frequencies, even though the tweeter-on-top concept was not appropriate.

Around this time, Kenneth was interested in exploring assymmetrical forms. We shall see some further concepts later in this article, but his original sketch for the Matrix 800 (Figure 8) was hardly changed on the way to the final striking product (Figure 9).

As befits this assymmetrical shape, the product was manufactured in mirrored pairs to ensure the symmetry essential for producing a balanced stereo image.

In 1990, an expanded 800 Series was developed with a more conventional aspect, but still retaining the tweeter-on-top concept first seen on the DM7.

Silver Signature and Signature 30 Anniversary speakers

Grange’s original designs were embellished on two occasions for products to celebrate important milestiones in the company’s history, each time with added technical features. The first of these – the Silver Signature – celebrated the 25th anniversary and was spawned from the stand-mount Matrix 805. Kenneth added a highly figured veneer, coupled with chrome plated trims and tweeter housing. Technically, the speaker boasted an improved bass/midrange driver, crossover components and silver cabling.

The second, shown in Figure 10, was the Signature 30 which, not surprisingly, came 5 years later for the 30th anniversary. This was developed from the floor-standing 2½-way Matrix 803 and we can see the same chrome trims and highly figured veneer, which was available in two variants – grey bird’s eye and tiger’s eye seen here.

These veneers are worth mentioning if only to explain the names, which bear no relation to any known species of tree. The Italian company, Alpi, specialises in creating highly repeatable, but often quite artificial patterns using real wood, mostly poplar. The base veneers, usually rotary cut from the log rather like sharpening a large pencil, are dyed and bonded together in multi-ply form. These may then be reshaped using steam and heat and cut in a different direction to produce thin veneers with grain patterns that may mimic real woods, but may also be quite geometric.

Fortunately help was close at hand. SME, the company known for its high quality turntables and tone arms is situated in the same village of Steyning as our R&D department. They had the necessary fine engineering capability to achieve the desired quality.

By 1998, Kenneth was past the age when normal people retire form full time work and indeed the number of projects undertaken with Bowers & Wilkins gradually reduced. But creative people never really stop doing what they love and in 2003 Kenneth was invited to undertake another milestone product.
The brief was sparse in the extreme. Kenneth was almost given carte blanche in the sure knowledge that by that time he knew without thinking what technical constraints are placed on speaker design.

Limited edition Signature Diamond speaker

The Signature Diamond, a limited edition product, was the result. Original models were presented in the white finish seen with and without grille in Figures 12 & 13. The company’s diamond dome tweeter was to be celebrated with a beautifully sculpted marble housing and the bass/midrange housed in an enclosure the like of which we had never manufactured before.

Technical challenges abounded. Indeed, the acoustic engineer assigned to the project, Dr John Dibb, even started out doubting the wisdom of allowing Kenneth to come up with an enclosure that promised problems from internal pipe resonance. As it turned out, the acoustic problems were fairly benign, but the mechanical ones were not, with one of the most difficult hurdles to clear being the joining of the forward facing tube carrying the driver with the tube of the main cabinet. The former was formed from an aluminium extrusion and the latter from layers of MDF, bent to shape. When subjected to natural changes in temperature and humidity, these two dissimilar materials suffer differential shrinkage, which can lead to cracking of the paint layer. That these problems were successfully overcome owed much to the skill of out in-house cabinet manufacture and paint shop.

As product manager for the project, I was privileged to travel to Italy with Kenneth to choose both the veneer for the alternative cabinet finish and the marble options for the tweeter housing. The veneer was yet another Alpi product and again we were presented with a pattern that defied description by any known wood grain pattern. The name Wakame was suggested by another of our engineers, Tom O’Brien, as the pattern reminded him of the seaweed served in Japanese restaurants. That version is seen in Figures 14 & 15.

Marble Tweeters

From the Alpi factory, we travelled over the Apennine mountains to the west coast just north of Pisa. There we visited a supplier of marble who also offered the ability to machine the material into the tactile shape Kenneth proposed. After much deliberation, two types of marble were chosen from a vast array, a different one for each cabinet finish. The difficult challenge of machining the marble to Kenneth’s complex freehand shape and then accurately positioning the precision cut-out for the tweeter unit itself we were happy to leave to our supplier!

Concept designs

Not all designs see the light of day as manufactured products. It’s actually rare for them simply not to be liked from an aesthetic point of view. Often they are not even discarded outright, but put on the back burner for another day. Like many others in his profession, Kenneth does not always design to a brief given by the manufacturer. He may want to pursue an idea and then present the design for consideration. That they are not taken up may be because the company does not have the need for such a model at that time. On other occasions, the concept may be beyond manufacturing capability at that time.

Below is a collection of very rare images of some of Kenneth’s designs that remain on that back burner.

9 Comments

Amazing design concepts. Been a B&W owner/fan for many years and although the newer designs have bettered previous models every time i’d be over the moon with a set of thoose beautiful looking CM2’s!!

Posted: Tuesday, 26 July 2011

mocha6ft3 says:

It’s quite amazing to see all the speakers that B&W have been working on from the past to the present. I admire all the work that is put into constructing fine speakers for us to enjoy. Thank you B&W for all your hard work. Perhaps one day i will be able to sit back and listen your fine speakers in my own home one day. Until then, i am forever a faithful admirer of your speakers. Thank you.

Posted: Tuesday, 26 July 2011

kail says:

simply speechless, wow

Posted: Saturday, 13 August 2011

Walrave says:

I owned the cm1/cm2 block since 1987, and I’m still using these wonderful boxes combination. But I’m completely disappointed for months now, my monoblock amplifier (an old one) has suddenly broken down, destroying at that moment the cm1 tweeter. I have tested the cm1 filter, there is no damage, but the twitter is out and I’m desperately looking for one. Simply, if you do have this one, or know someone who has a 1987 cm1 generation, please contact me, my email address is jeans6565@gmail.com
Thanks for your help, and thanks B&W who really makes me discovering all the JS Bach mathematical suit in his harpsichord (even if I prefer the piano translation, but of course, I own the 804 D)

Posted: Sunday, 30 October 2011

Linda says:

How much would a pair of B&W DM7 speakers go for?

Posted: Thursday, 23 February 2012

Paul F says:

I have owned a pair of Concept 90 CM1/CM2 speakers since May 1988 and have used them almost daily. The speakers are the only part of my Hi-Fi system that I haven’t felt the need to upgrade over the years due to the simple fact that the better my amps and sources have become the better these speakers sound. Currently they are hooked up to a Musical Fidelity KW500 Dual Mono Integrated amp that has been fully upgraded by JS Audio, a Michell Orbe deck with SME Series V arm and Ortofon MC500 cartridge, Trichord Delphini phono stage and JS Audio upgraded Musical Fidelity Tri-Vista 21 DAC with a home built music server. Although the recommended amps for these speakers are 50W-200W they simply thrive with the KW500 Watt amp. The sounsstage is vast and all types of music sound truly fabulous. The HF & MF are crystal clear and the base from these relatively small cabinets is nothing short of remarkable. Oh and to top it all I have never had to have any parts replaced on the speakers. A fantastic build quality. What else can you buy that will last you nearly 25 years and still be as good as the day you bought it? hats off to Kenneth Grange & Bowers & Wilkins.

Posted: Thursday, 18 October 2012

David Simpkins says:

I also still use daily my Concept 90 CM2’s I purchased in the late 80’s when I managed a B&W dealership. I am still amazed how “musical” they are – they are about enjoying the music, not “shouting detail to impress” Although £1,000 for a pair new in the late 80’s was a lot of money, £40 per annum for the amount of pleasure they have delivered over the last 25 years is the bargain of the century!

Posted: Wednesday, 20 November 2013

jon b says:

most butiful designs ever made.
i had a pair of dm 14 that was very nice.i bougth them mint in box.
loved the sound in thoose but i like bass.
so i got my self a pair of dm6:) then i was pleased running thrugh
threshold sl-10 and modifed 400a.
all i can say is magic:) to my eyes and ears

Posted: Thursday, 26 December 2013

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Posted: Tuesday, 17 February 2015

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